1. Field of the Invention
The present invention relates to an inkjet recording apparatus which enables knowing how much ink remains in the ink tubes when the ink cover that covers the ink cartridge is open, and to an ink management method for this inkjet recording apparatus.
2. Description of the Related Art
Inkjet recording apparatuses, referred to herein as simply inkjet printers, are relatively quiet when printing, can print very fine dots at a very high density, and have thus found many uses in color printing and other applications. Inkjet printers of this type typically have an inkjet recording (print) head that is mounted on a carriage and moves widthwise to the paper or other recording medium, and a paper transportation assembly that conveys the recording medium relative to the print head in a direction perpendicular to the direction of print head movement. Ink is discharged from the print head based on print data to print on the paper or other recording medium.
If the print head mounted on the carriage has elements for discharging black, yellow, cyan, and magenta ink, the printer is not limited to printing text using black ink and can be used for full-color printing by controlling the discharge ratio of each color of ink. See, for example, Japanese Unexamined Patent Appl. Pub. 2002-200749.
The mechanism for installing and removing an ink cartridge to the ink cartridge holder in this type of printer generally has an ink supply nozzle disposed to the ink cartridge mounting portion of the cartridge holder. An ink suction opening formed in the ink cartridge is then inserted over this ink supply nozzle and the ink cartridge is slid into place on the cartridge holder.
This mechanism for installing and removing the ink cartridge assumes using an ink cartridge having a flexible ink sack that is filled with ink, an ink suction opening formed in the ink sack for drawing ink from the sack, and a rectangular rigid plastic case in which the ink sack is held. See, for example, Japanese Unexamined Patent Appl. Pub. H05-16378.
The ink suction opening formed in the ink sack is exposed from the front of the rigid plastic case. The ink supply nozzle rendered on the ink cartridge mounting portion of the cartridge holder of the inkjet printer can therefore be inserted to this ink suction opening so that ink can be drawn from the ink sack.
When ink cartridges are repeatedly installed and removed from the cartridge holder of the ink cartridge installation mechanism in this conventional inkjet recording apparatus, the portion of the ink supply nozzle that is inserted to the ink suction opening of the ink sack gradually becomes fatigued and may become deformed, resulting in a gap between the nozzle and the ink sack opening. Ink inside the ink cartridge and in the ink tube communicating the ink cartridge with the print head can then leak to the outside from this gap.
Furthermore, when an ink cartridge is loaded in the cartridge holder, opening the ink cover of the cartridge holder to remove the ink cartridge relieves the pressure applied to the ink cartridge by the ink pressure pump.
A problem with this arrangement is that while the pressure decreases gradually, the pressure is still high for the first few seconds after the cover opens, and ink remaining in the ink cartridge and in the tubes communicating the ink cartridge with the print head leaks outside from the connection between the ink supply nozzle and the ink suction opening in the ink sack.
A sponge or other ink absorbing material is therefore used to absorb the ink leaking from this cartridge connection and prevent ink from pooling in or adhering to the cartridge holder. As a result, the ink cartridge can also be replaced without getting your hands dirty.
A problem with the foregoing prior art is that the size of the ink absorbing material disposed in the conventional cartridge holder is limited due to design limitations, for example, and the ink absorption capacity is therefore small. As a result, if the volume of the leaked ink exceeds the ink absorption capacity of the ink absorbing material, the ink will overflow into the cartridge holder, thus soiling the inside of the cartridge holder. The user's hands thus also get dirty when replacing the ink cartridge.
The present invention solves this problem by providing an inkjet recording apparatus and an ink management method for the same that prevents ink from soiling the cartridge holder by first determining the remaining ink volume and prompting the user to replace the ink absorbing material with an ink absorbing material having sufficient thickness and ink absorption capacity.